Brought to its knees at the end of the last decade by successive lay- offs among the Big Three car manufacturers, Detroit, or, as the record label dubbed it, Motown, is about to live through a phenomenal hiring boom.

The jobs bonanza, outlined in a study just released by the University of Michigan, will not come from the recent sharp recovery in the car industry's fortunes, although recovery there has surely been, with all three car makers now in profit. Rather, it is a question of demographics.

According to the study, the Big Three, Ford, Chrysler and General Motors, are facing a formidable "retirement bubble", with no less than 241,969 workers due to take their pension within the next eight years. Depending on the industry's growth, this should translate into up to a quarter of a million new hires.

"The auto industry has not been a source of new hires for 20 years," said Brett Smith, one of the study's authors. "There's going to be a major change in that, purely for retirement reasons".

For Michigan in particular, where the US car industry is still largely concentrated, the report spells wonderful economic news. It is also a boon for the state's Republican governor, John Engler, who is sometimes mentioned as a future presidential candidate for his party. Michigan lost no less than 194,000 jobs in the car industry during its darkest years from 1978 to 1994.

The change, however, presents the state with a daunting challenge if it is to supply the necessary number of sufficiently educated and trained applicants. New technologies in particular mean that the manufacturers will no longer be interested in untrained labour straight from school.

"In the 1960s and 70s, it was easy to walk out of a high school in Flint [Michigan] and get a job in an auto plant," commented Mr Smith. "Now it's going to be difficult to do that".